Fuel feeding apparatus



Dec. 10, 1940. H. J. FINDER FUEL FEEDING APPARATUS 2 Sheets-Sheecl l yFiled March 1, 1939..

(Ittornegs' Dec. 10, 1940. Y H J, PlNDER 2,224,797

FUEL FEEDING APPARATUS Filed Mwah 1, 1939 2 sheets-sheet 2 Gttornegsstant as possible.

Patented Dec. 10, 1940 PATENT- OFFICE 2,224,191 FUEL FEEDmG APPARATUS lVHarold J. Pinder, Charles Town, W. Va., asslgnor to The Standard Limeand Stone Company, Baltimore, Md., a corporation of Maryland ApplicationMarch l1, 1 939, serial No. 259,289

4 Claims.

Thisinvention pertains to a fuel feeding or stoking mechanism, and hasfor its object the production of a structure which will feed the fuel,say coal, to a stationary fire bed in such a manner that the coal willhave an opportunity to burn beyond the coking stage prior to theintroduction of an additional charge onto the previously placed charge.y

The structure also provides means for successively feeding fuel,hereinafter referred toas coal. to different lpoints or zones upon thebed and placing successive charges at such points,.where by the coal isburned to the greatest advantage and the temperature is maintained asnearly con- The structure has been used primarily for heating retortsfor the treatment of materials for the production of lime, especiallywhere the fuel feeding mechanism is subjected to high temperatureshaving a tendency to warp or distort the operating parts, although it isapplicable to use in any branch of industry where a relatively fixed andgiven temperatureis desirable in the operation of the plant.

Various advantages of the structure herein described, which has provenhighly satisfactory in numerous installations, will appear in thefollowing speciflcation and reference is had to the annexed drawings,wherein- Figure 1 is a perspective view of the structure as a whole, theroof or arch of the furnace being broken away in part to show theunderlying coal bed;

Fig. 2, a longitudinal vertical sectional View of the feeding apparatus,with parts'ln elevation;

Fig. 3, a transverse sectional view taken on the line III--III of Fig.2; and

Fig. 4, a plan view showing different units for feeding various furnacesfrom a commonsource of power.

'Ihe structure is such that the rate and volume of the feed to anyparticular point upon the bed of fuel within the furnace may beregulated to bring about the best combustion results. Furthermore, thefeeding elements are water-cooled throughout, whereby warping andsticking of the movable parts is precluded. The structure is shown asfeeding to three points or zones upon the furnace bed, although it willbe understood that it may be a greater or less number of points.

The feeding mechanism is located above the furnace I Il and is supportedupon a floor or platform denoted by II. The mechanism will, of course,be formed of metal and the main body may be said to comprise a housingfor the rotatable charge feeding element. The housing ls denoted by I2and there is formed in the upper portion thereof a cylindrical chamberI3, the upf per portion of which extends above the housing l2 and isprovided with three separate openims 5 I4. These openings stand inalignment with'the lower end of a feed hopper for coal, denotedgenerally by I5 and subdivided by cross-partitions I5I (Fig. 2). Slidevalves I6, one for each opening, movable on anglepieces II attached tothe partitions I5l and to the ends of the hopper wall, underlie thelower end of the hopper so that they may cut olf fuel from feedingdownwardly into the apparatus if for any reason it becomes necessary soto do. l l5 Extending from the lower portion of the cylindrical chamberI3 and in line with openings Il formed in the lower section thereof arechutes I8, one for each opening, which, as best seen in Fig. 1, extendthrough the furnace arch and terminate above the fire bed. The outermostchutes diverge from the central one so that the feed of the coal takesplace at separate points or areas upon the burning coal bed.

The charge feeding structure is mounted within .the cylindrical chamberI3. It may be said to comprise a hollow cylindrical member or drum I9provided' with a series of separate longitudinally spaced radial pockets2| preferably spaced peripherally about the member as indicated indotted lines in Fig. 3. In other words. the open outer ends of thesepockets are offset with reference to each other, so that the coal is notfed simultaneously from all of them or, in fact, from any two of them.The cubical capacity of the pockets 2| may be varied by securing fillerpieces 22 in the bottom thereof, as best shown in Fig. 3. Any othermeans for varying the capacity may, however, be employed. Each of thechambers formed in the bottom of the hopper I5 is laterally 40accessible through openings formed in their sides and closed by coverplates 2Il.v This permits access to the interior of the chambers forrepairing,- inspection, or cleaning of the parts as well as to permitready substitution of different filler pieces in the radial pockets. Thepockets 2| are not in communication at any point with the interior ofthe hollow drum, as this drum is designed to be cooled by water passingthrough the same.

The drum I9 is supported by a hollow drive 50 shaft 23 extending throughthe end wall 24. The shaft is welded or otherwise secured to the end ofthe drum', and also passes through a second wall or partition 25 xedlysecured within the drum a short distance from the wall 2l. The end 55 ofthe shaft is thus supported by the two walls to maintain its A alignmentwith its'beng 2l through the walls and is secured thereto. 'I'his shaftrotates in a bearing 26n similar to bearing 23. 'I'he outer end `of theshaft- 3I is in communication with an inlet water pipe 32 through asuitable nxture 33 of any approved type. Hence, water may circulatethrough shaft 3l from inlet 32, through the interior of the drum I9 incontact with the walls of the fuel pockets and out of the shaft 23.Means are provided to impart a step-by-step rotative movement to thecylindrical feeding member I9, and to that end a series Aof differentsized ratchetwheels 34, 35 and 33.

are secured to the shaft 23, the ratchets andi)` consequently the shaft,being driven through a i, pawl mechanism best shown in Figgl.

Mounted upon the platform I I is an electric, motor 31, the shaft ofwhich is interconnected, with reduction gearing housed at 38 which,turn, is connected through a flexible coupling 39 with a shaft 4Imounted in a bearing 42. Shaft 4I carries a pinion 43 which meshes witha gear 44 secured to a shaft 45 mounted in bearings 46 and 41. 'I'heshaft 45 has secured to it a pair of eccentrics 48 and 49 vsurrounded bystraps 5I and 52, from which extend arms 53 and 54, respectively. In theouter free ends of said arms, which extend toward the ratchet wheelsheretofore referred to, is a shaft 50 upon which are pivotally mounted aseries of pawls, one for each ratchet wheel, the pawls being4 denoted55, 53 and 51, respectively. Through the utilization of these pawls andthe different sized ratchet wheels, variable speeds of rotation partedto the cylindrical member I9.

As will be readily appreciated, if the pawl 55 is thrown forward intoworking relation with the large ratchet wheel 36, a relatively slowmotion will be imparted to the charge feeding element. At that time theother two pawls may be thrown backward out of contact with their wheels,and will ride idly on the same. The speed may be increased by throwingone or the other of the pawls 56, 51 into working relation with itsrespective ratchet wheel.

As best shown in Figs. 2 and 3. the clearance provided between therotating drum I9 and the may ybe imcylindrical chamber I3 is reduced toa minimum in order to limit to a negligible quantity 'the amount vofhighly heated gases passing between the periphery ofthe drum and thecylindrical chamber. This prevents warping and consequent binding of theparts and, likewise', prevents -coal from sticking to the surface of thedrum. Otherwise, overheating of the parts would cause hot fine coal togradually clog the space between the surfaces of the parts.

The passage of gas upwardly from the furnace through the members I3 andaround the space between the elements I3 and I9 is negligible, whilepassage through the hopper is precluded by the body of coal therein.Ordinarily, the apparatus will be mounted in the open air, hence theescape of gas upwardly will be of no consequence except for the possibleloss of a small volume of the heat units.

Upon referenceto Fig. 3, it-will be noted that ,l

water may be maintained within the hollow boxlike body to keep the partscool. The rotating drum is alsocooled by the introduction of waterthrough. the hollow shaft 3| and the outilow thereof through shaft23'and allied parts. Consequently. the fuel feeding drum and its chargesare cooled by water circulating within the drum. Thus, the temperatureis held to a satisfactory value regardless of adverse conditions oflocation. In cool weather if the installation is out of doors, there isno necessity for water cooling, as has been demonstrated by actualoperation of the apparatus.

In Fig. 4, a layout is shown wherein four `feeding units, A, B, C andD.of the type above described may be driven from a common motor throughsuitable extensions of the shaft comparable to the shaft 45interconnected by across driving chain E. 'I'he motor in this instanceis denoted by 31@ and the reduction gear and other parts remain the sameas heretofore described.

In resum lit may be said that each division of the feed hopperdischarges fuel directly to a pocket in the cylindrical member or drum.As the drum rotates step-by-step about its axis, it discharges fuel tothe associated chute I9,thence toy a definite place or zone in thefurnace, delivery being flxed in position and timed in accordance withthe spacing of the pockets in the rotating drum and its speed, as aboveset forth. This accomplishes the burning of the coal beyond the cokingstage before another supply of coal is delivered at that particularpoint inthe furnace. With this arrangement, smothering of the tlre isprevented and a new charge of coal is always introduced to theparticular zone when it is required. Continuous delivery of coal to afurnace bed is notl successful, due to the building up of coke in thefurnace. It has been found in actual use ofthe present intermittentstoking apparatus in comparing it with methods of continuous stoking,that the output of lime per kiln where the same kilns are employed, isincreased, by use of the present invention, from 9 tons per day to 13tons per day, and this is accompanied by a material reduction in theamount of fuel burned.

What is claimed is:

1.A In a fuel feeding apparatus, the combination of a hollow casinghaving a longitudinally extending cylindrical member located therein,said member having a series of openings in the upper portion thereofabove the casing and a series of openings ,in the lowerportion thereof;a chute leading from each of said last named openings; a hopper locatedabove the cylindrical member in line with the openings in the upperportion thereof; a pocketed member rotatably mounted within saidcylindrical member, the pockets being spaced circumferentially about thecylindrical member and spaced longitudinally thereof; means forimparting a step-by-step rotative movement to said pocketed member; andmeans for passing cooling water through the rotatable v thereof. saidmember having a series of pockets formed therein; means for introducingcooling `medium into the member and outside of the pockets; openings inthe uppermost portion of said chamber for delivering fuel to saidpockets as the open ends thereof are in their uppermost positions;chutes communicating with openings formedvin the lower portion of thecylindrical chamber and registering successively with the.

rotates; means forimparting rotative movement to said cylindricalmember; and means for varying said movement in. accordance with varyingconditions of operation'. 1

3. In an intermittent fuel feeding apparatus. a water-cooled casinghaving registering openings in its upper and lower portions; a fuelhopper mounted on said casing and having separate fuel dischargeportions communicating with the openings in the upper portion of saidchamber: a hollow rotatable member located in said casing and havingradial pocketsadapted for successive registry with `the upper and loweropenings in said casing: means for passing water through said hollowrotatablemember to cool the same; a fuel discharge chute connected witheach of the openings in the lower portion of the casing; means forrotating said member; and means for varying the speed of rotation ofsaid member.

4. In an intermittent fuel feeding apparatus, a water-cooled casinghaving a cylindrical chamber\formed therein and containing alignedopeningsin its top and bottom portions; a fuel hopper carried on top ofsaid casing and having fuel discharge openings communicating with theopenings in the top of said chamber; a drum rotatably e mounted insaidchamber and having staggered radial fuel pockets adapted forsuccessive registry with the top and bottom openings in said chamber asthe drum rotates; fuel discharge chutes leading from the openings in thebottom of said chamber; means for uid cooling the exterior of saidcylindrical chamber; means for fluid cooling the interior of said`drum;and means for rotating said drum to feed charges of fuel from saidhopper into said fuel discharge chutes in succession.

HAROLD J. FINDER.

